1 /* 2 * linux/kernel/irq/manage.c 3 * 4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar 5 * Copyright (C) 2005-2006 Thomas Gleixner 6 * 7 * This file contains driver APIs to the irq subsystem. 8 */ 9 10 #define pr_fmt(fmt) "genirq: " fmt 11 12 #include <linux/irq.h> 13 #include <linux/kthread.h> 14 #include <linux/module.h> 15 #include <linux/random.h> 16 #include <linux/interrupt.h> 17 #include <linux/slab.h> 18 #include <linux/sched.h> 19 #include <linux/sched/rt.h> 20 #include <linux/sched/task.h> 21 #include <uapi/linux/sched/types.h> 22 #include <linux/task_work.h> 23 24 #include "internals.h" 25 26 #ifdef CONFIG_IRQ_FORCED_THREADING 27 __read_mostly bool force_irqthreads; 28 29 static int __init setup_forced_irqthreads(char *arg) 30 { 31 force_irqthreads = true; 32 return 0; 33 } 34 early_param("threadirqs", setup_forced_irqthreads); 35 #endif 36 37 static void __synchronize_hardirq(struct irq_desc *desc) 38 { 39 bool inprogress; 40 41 do { 42 unsigned long flags; 43 44 /* 45 * Wait until we're out of the critical section. This might 46 * give the wrong answer due to the lack of memory barriers. 47 */ 48 while (irqd_irq_inprogress(&desc->irq_data)) 49 cpu_relax(); 50 51 /* Ok, that indicated we're done: double-check carefully. */ 52 raw_spin_lock_irqsave(&desc->lock, flags); 53 inprogress = irqd_irq_inprogress(&desc->irq_data); 54 raw_spin_unlock_irqrestore(&desc->lock, flags); 55 56 /* Oops, that failed? */ 57 } while (inprogress); 58 } 59 60 /** 61 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs) 62 * @irq: interrupt number to wait for 63 * 64 * This function waits for any pending hard IRQ handlers for this 65 * interrupt to complete before returning. If you use this 66 * function while holding a resource the IRQ handler may need you 67 * will deadlock. It does not take associated threaded handlers 68 * into account. 69 * 70 * Do not use this for shutdown scenarios where you must be sure 71 * that all parts (hardirq and threaded handler) have completed. 72 * 73 * Returns: false if a threaded handler is active. 74 * 75 * This function may be called - with care - from IRQ context. 76 */ 77 bool synchronize_hardirq(unsigned int irq) 78 { 79 struct irq_desc *desc = irq_to_desc(irq); 80 81 if (desc) { 82 __synchronize_hardirq(desc); 83 return !atomic_read(&desc->threads_active); 84 } 85 86 return true; 87 } 88 EXPORT_SYMBOL(synchronize_hardirq); 89 90 /** 91 * synchronize_irq - wait for pending IRQ handlers (on other CPUs) 92 * @irq: interrupt number to wait for 93 * 94 * This function waits for any pending IRQ handlers for this interrupt 95 * to complete before returning. If you use this function while 96 * holding a resource the IRQ handler may need you will deadlock. 97 * 98 * This function may be called - with care - from IRQ context. 99 */ 100 void synchronize_irq(unsigned int irq) 101 { 102 struct irq_desc *desc = irq_to_desc(irq); 103 104 if (desc) { 105 __synchronize_hardirq(desc); 106 /* 107 * We made sure that no hardirq handler is 108 * running. Now verify that no threaded handlers are 109 * active. 110 */ 111 wait_event(desc->wait_for_threads, 112 !atomic_read(&desc->threads_active)); 113 } 114 } 115 EXPORT_SYMBOL(synchronize_irq); 116 117 #ifdef CONFIG_SMP 118 cpumask_var_t irq_default_affinity; 119 120 static bool __irq_can_set_affinity(struct irq_desc *desc) 121 { 122 if (!desc || !irqd_can_balance(&desc->irq_data) || 123 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity) 124 return false; 125 return true; 126 } 127 128 /** 129 * irq_can_set_affinity - Check if the affinity of a given irq can be set 130 * @irq: Interrupt to check 131 * 132 */ 133 int irq_can_set_affinity(unsigned int irq) 134 { 135 return __irq_can_set_affinity(irq_to_desc(irq)); 136 } 137 138 /** 139 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space 140 * @irq: Interrupt to check 141 * 142 * Like irq_can_set_affinity() above, but additionally checks for the 143 * AFFINITY_MANAGED flag. 144 */ 145 bool irq_can_set_affinity_usr(unsigned int irq) 146 { 147 struct irq_desc *desc = irq_to_desc(irq); 148 149 return __irq_can_set_affinity(desc) && 150 !irqd_affinity_is_managed(&desc->irq_data); 151 } 152 153 /** 154 * irq_set_thread_affinity - Notify irq threads to adjust affinity 155 * @desc: irq descriptor which has affitnity changed 156 * 157 * We just set IRQTF_AFFINITY and delegate the affinity setting 158 * to the interrupt thread itself. We can not call 159 * set_cpus_allowed_ptr() here as we hold desc->lock and this 160 * code can be called from hard interrupt context. 161 */ 162 void irq_set_thread_affinity(struct irq_desc *desc) 163 { 164 struct irqaction *action; 165 166 for_each_action_of_desc(desc, action) 167 if (action->thread) 168 set_bit(IRQTF_AFFINITY, &action->thread_flags); 169 } 170 171 static void irq_validate_effective_affinity(struct irq_data *data) 172 { 173 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK 174 const struct cpumask *m = irq_data_get_effective_affinity_mask(data); 175 struct irq_chip *chip = irq_data_get_irq_chip(data); 176 177 if (!cpumask_empty(m)) 178 return; 179 pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n", 180 chip->name, data->irq); 181 #endif 182 } 183 184 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, 185 bool force) 186 { 187 struct irq_desc *desc = irq_data_to_desc(data); 188 struct irq_chip *chip = irq_data_get_irq_chip(data); 189 int ret; 190 191 if (!chip || !chip->irq_set_affinity) 192 return -EINVAL; 193 194 ret = chip->irq_set_affinity(data, mask, force); 195 switch (ret) { 196 case IRQ_SET_MASK_OK: 197 case IRQ_SET_MASK_OK_DONE: 198 cpumask_copy(desc->irq_common_data.affinity, mask); 199 case IRQ_SET_MASK_OK_NOCOPY: 200 irq_validate_effective_affinity(data); 201 irq_set_thread_affinity(desc); 202 ret = 0; 203 } 204 205 return ret; 206 } 207 208 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask, 209 bool force) 210 { 211 struct irq_chip *chip = irq_data_get_irq_chip(data); 212 struct irq_desc *desc = irq_data_to_desc(data); 213 int ret = 0; 214 215 if (!chip || !chip->irq_set_affinity) 216 return -EINVAL; 217 218 if (irq_can_move_pcntxt(data)) { 219 ret = irq_do_set_affinity(data, mask, force); 220 } else { 221 irqd_set_move_pending(data); 222 irq_copy_pending(desc, mask); 223 } 224 225 if (desc->affinity_notify) { 226 kref_get(&desc->affinity_notify->kref); 227 schedule_work(&desc->affinity_notify->work); 228 } 229 irqd_set(data, IRQD_AFFINITY_SET); 230 231 return ret; 232 } 233 234 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force) 235 { 236 struct irq_desc *desc = irq_to_desc(irq); 237 unsigned long flags; 238 int ret; 239 240 if (!desc) 241 return -EINVAL; 242 243 raw_spin_lock_irqsave(&desc->lock, flags); 244 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force); 245 raw_spin_unlock_irqrestore(&desc->lock, flags); 246 return ret; 247 } 248 249 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) 250 { 251 unsigned long flags; 252 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 253 254 if (!desc) 255 return -EINVAL; 256 desc->affinity_hint = m; 257 irq_put_desc_unlock(desc, flags); 258 /* set the initial affinity to prevent every interrupt being on CPU0 */ 259 if (m) 260 __irq_set_affinity(irq, m, false); 261 return 0; 262 } 263 EXPORT_SYMBOL_GPL(irq_set_affinity_hint); 264 265 static void irq_affinity_notify(struct work_struct *work) 266 { 267 struct irq_affinity_notify *notify = 268 container_of(work, struct irq_affinity_notify, work); 269 struct irq_desc *desc = irq_to_desc(notify->irq); 270 cpumask_var_t cpumask; 271 unsigned long flags; 272 273 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL)) 274 goto out; 275 276 raw_spin_lock_irqsave(&desc->lock, flags); 277 if (irq_move_pending(&desc->irq_data)) 278 irq_get_pending(cpumask, desc); 279 else 280 cpumask_copy(cpumask, desc->irq_common_data.affinity); 281 raw_spin_unlock_irqrestore(&desc->lock, flags); 282 283 notify->notify(notify, cpumask); 284 285 free_cpumask_var(cpumask); 286 out: 287 kref_put(¬ify->kref, notify->release); 288 } 289 290 /** 291 * irq_set_affinity_notifier - control notification of IRQ affinity changes 292 * @irq: Interrupt for which to enable/disable notification 293 * @notify: Context for notification, or %NULL to disable 294 * notification. Function pointers must be initialised; 295 * the other fields will be initialised by this function. 296 * 297 * Must be called in process context. Notification may only be enabled 298 * after the IRQ is allocated and must be disabled before the IRQ is 299 * freed using free_irq(). 300 */ 301 int 302 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) 303 { 304 struct irq_desc *desc = irq_to_desc(irq); 305 struct irq_affinity_notify *old_notify; 306 unsigned long flags; 307 308 /* The release function is promised process context */ 309 might_sleep(); 310 311 if (!desc) 312 return -EINVAL; 313 314 /* Complete initialisation of *notify */ 315 if (notify) { 316 notify->irq = irq; 317 kref_init(¬ify->kref); 318 INIT_WORK(¬ify->work, irq_affinity_notify); 319 } 320 321 raw_spin_lock_irqsave(&desc->lock, flags); 322 old_notify = desc->affinity_notify; 323 desc->affinity_notify = notify; 324 raw_spin_unlock_irqrestore(&desc->lock, flags); 325 326 if (old_notify) 327 kref_put(&old_notify->kref, old_notify->release); 328 329 return 0; 330 } 331 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier); 332 333 #ifndef CONFIG_AUTO_IRQ_AFFINITY 334 /* 335 * Generic version of the affinity autoselector. 336 */ 337 int irq_setup_affinity(struct irq_desc *desc) 338 { 339 struct cpumask *set = irq_default_affinity; 340 int ret, node = irq_desc_get_node(desc); 341 static DEFINE_RAW_SPINLOCK(mask_lock); 342 static struct cpumask mask; 343 344 /* Excludes PER_CPU and NO_BALANCE interrupts */ 345 if (!__irq_can_set_affinity(desc)) 346 return 0; 347 348 raw_spin_lock(&mask_lock); 349 /* 350 * Preserve the managed affinity setting and a userspace affinity 351 * setup, but make sure that one of the targets is online. 352 */ 353 if (irqd_affinity_is_managed(&desc->irq_data) || 354 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) { 355 if (cpumask_intersects(desc->irq_common_data.affinity, 356 cpu_online_mask)) 357 set = desc->irq_common_data.affinity; 358 else 359 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET); 360 } 361 362 cpumask_and(&mask, cpu_online_mask, set); 363 if (node != NUMA_NO_NODE) { 364 const struct cpumask *nodemask = cpumask_of_node(node); 365 366 /* make sure at least one of the cpus in nodemask is online */ 367 if (cpumask_intersects(&mask, nodemask)) 368 cpumask_and(&mask, &mask, nodemask); 369 } 370 ret = irq_do_set_affinity(&desc->irq_data, &mask, false); 371 raw_spin_unlock(&mask_lock); 372 return ret; 373 } 374 #else 375 /* Wrapper for ALPHA specific affinity selector magic */ 376 int irq_setup_affinity(struct irq_desc *desc) 377 { 378 return irq_select_affinity(irq_desc_get_irq(desc)); 379 } 380 #endif 381 382 /* 383 * Called when a bogus affinity is set via /proc/irq 384 */ 385 int irq_select_affinity_usr(unsigned int irq) 386 { 387 struct irq_desc *desc = irq_to_desc(irq); 388 unsigned long flags; 389 int ret; 390 391 raw_spin_lock_irqsave(&desc->lock, flags); 392 ret = irq_setup_affinity(desc); 393 raw_spin_unlock_irqrestore(&desc->lock, flags); 394 return ret; 395 } 396 #endif 397 398 /** 399 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt 400 * @irq: interrupt number to set affinity 401 * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU 402 * specific data for percpu_devid interrupts 403 * 404 * This function uses the vCPU specific data to set the vCPU 405 * affinity for an irq. The vCPU specific data is passed from 406 * outside, such as KVM. One example code path is as below: 407 * KVM -> IOMMU -> irq_set_vcpu_affinity(). 408 */ 409 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info) 410 { 411 unsigned long flags; 412 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); 413 struct irq_data *data; 414 struct irq_chip *chip; 415 int ret = -ENOSYS; 416 417 if (!desc) 418 return -EINVAL; 419 420 data = irq_desc_get_irq_data(desc); 421 do { 422 chip = irq_data_get_irq_chip(data); 423 if (chip && chip->irq_set_vcpu_affinity) 424 break; 425 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY 426 data = data->parent_data; 427 #else 428 data = NULL; 429 #endif 430 } while (data); 431 432 if (data) 433 ret = chip->irq_set_vcpu_affinity(data, vcpu_info); 434 irq_put_desc_unlock(desc, flags); 435 436 return ret; 437 } 438 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity); 439 440 void __disable_irq(struct irq_desc *desc) 441 { 442 if (!desc->depth++) 443 irq_disable(desc); 444 } 445 446 static int __disable_irq_nosync(unsigned int irq) 447 { 448 unsigned long flags; 449 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 450 451 if (!desc) 452 return -EINVAL; 453 __disable_irq(desc); 454 irq_put_desc_busunlock(desc, flags); 455 return 0; 456 } 457 458 /** 459 * disable_irq_nosync - disable an irq without waiting 460 * @irq: Interrupt to disable 461 * 462 * Disable the selected interrupt line. Disables and Enables are 463 * nested. 464 * Unlike disable_irq(), this function does not ensure existing 465 * instances of the IRQ handler have completed before returning. 466 * 467 * This function may be called from IRQ context. 468 */ 469 void disable_irq_nosync(unsigned int irq) 470 { 471 __disable_irq_nosync(irq); 472 } 473 EXPORT_SYMBOL(disable_irq_nosync); 474 475 /** 476 * disable_irq - disable an irq and wait for completion 477 * @irq: Interrupt to disable 478 * 479 * Disable the selected interrupt line. Enables and Disables are 480 * nested. 481 * This function waits for any pending IRQ handlers for this interrupt 482 * to complete before returning. If you use this function while 483 * holding a resource the IRQ handler may need you will deadlock. 484 * 485 * This function may be called - with care - from IRQ context. 486 */ 487 void disable_irq(unsigned int irq) 488 { 489 if (!__disable_irq_nosync(irq)) 490 synchronize_irq(irq); 491 } 492 EXPORT_SYMBOL(disable_irq); 493 494 /** 495 * disable_hardirq - disables an irq and waits for hardirq completion 496 * @irq: Interrupt to disable 497 * 498 * Disable the selected interrupt line. Enables and Disables are 499 * nested. 500 * This function waits for any pending hard IRQ handlers for this 501 * interrupt to complete before returning. If you use this function while 502 * holding a resource the hard IRQ handler may need you will deadlock. 503 * 504 * When used to optimistically disable an interrupt from atomic context 505 * the return value must be checked. 506 * 507 * Returns: false if a threaded handler is active. 508 * 509 * This function may be called - with care - from IRQ context. 510 */ 511 bool disable_hardirq(unsigned int irq) 512 { 513 if (!__disable_irq_nosync(irq)) 514 return synchronize_hardirq(irq); 515 516 return false; 517 } 518 EXPORT_SYMBOL_GPL(disable_hardirq); 519 520 void __enable_irq(struct irq_desc *desc) 521 { 522 switch (desc->depth) { 523 case 0: 524 err_out: 525 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", 526 irq_desc_get_irq(desc)); 527 break; 528 case 1: { 529 if (desc->istate & IRQS_SUSPENDED) 530 goto err_out; 531 /* Prevent probing on this irq: */ 532 irq_settings_set_noprobe(desc); 533 /* 534 * Call irq_startup() not irq_enable() here because the 535 * interrupt might be marked NOAUTOEN. So irq_startup() 536 * needs to be invoked when it gets enabled the first 537 * time. If it was already started up, then irq_startup() 538 * will invoke irq_enable() under the hood. 539 */ 540 irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE); 541 break; 542 } 543 default: 544 desc->depth--; 545 } 546 } 547 548 /** 549 * enable_irq - enable handling of an irq 550 * @irq: Interrupt to enable 551 * 552 * Undoes the effect of one call to disable_irq(). If this 553 * matches the last disable, processing of interrupts on this 554 * IRQ line is re-enabled. 555 * 556 * This function may be called from IRQ context only when 557 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL ! 558 */ 559 void enable_irq(unsigned int irq) 560 { 561 unsigned long flags; 562 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 563 564 if (!desc) 565 return; 566 if (WARN(!desc->irq_data.chip, 567 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq)) 568 goto out; 569 570 __enable_irq(desc); 571 out: 572 irq_put_desc_busunlock(desc, flags); 573 } 574 EXPORT_SYMBOL(enable_irq); 575 576 static int set_irq_wake_real(unsigned int irq, unsigned int on) 577 { 578 struct irq_desc *desc = irq_to_desc(irq); 579 int ret = -ENXIO; 580 581 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE) 582 return 0; 583 584 if (desc->irq_data.chip->irq_set_wake) 585 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on); 586 587 return ret; 588 } 589 590 /** 591 * irq_set_irq_wake - control irq power management wakeup 592 * @irq: interrupt to control 593 * @on: enable/disable power management wakeup 594 * 595 * Enable/disable power management wakeup mode, which is 596 * disabled by default. Enables and disables must match, 597 * just as they match for non-wakeup mode support. 598 * 599 * Wakeup mode lets this IRQ wake the system from sleep 600 * states like "suspend to RAM". 601 */ 602 int irq_set_irq_wake(unsigned int irq, unsigned int on) 603 { 604 unsigned long flags; 605 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 606 int ret = 0; 607 608 if (!desc) 609 return -EINVAL; 610 611 /* wakeup-capable irqs can be shared between drivers that 612 * don't need to have the same sleep mode behaviors. 613 */ 614 if (on) { 615 if (desc->wake_depth++ == 0) { 616 ret = set_irq_wake_real(irq, on); 617 if (ret) 618 desc->wake_depth = 0; 619 else 620 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE); 621 } 622 } else { 623 if (desc->wake_depth == 0) { 624 WARN(1, "Unbalanced IRQ %d wake disable\n", irq); 625 } else if (--desc->wake_depth == 0) { 626 ret = set_irq_wake_real(irq, on); 627 if (ret) 628 desc->wake_depth = 1; 629 else 630 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE); 631 } 632 } 633 irq_put_desc_busunlock(desc, flags); 634 return ret; 635 } 636 EXPORT_SYMBOL(irq_set_irq_wake); 637 638 /* 639 * Internal function that tells the architecture code whether a 640 * particular irq has been exclusively allocated or is available 641 * for driver use. 642 */ 643 int can_request_irq(unsigned int irq, unsigned long irqflags) 644 { 645 unsigned long flags; 646 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); 647 int canrequest = 0; 648 649 if (!desc) 650 return 0; 651 652 if (irq_settings_can_request(desc)) { 653 if (!desc->action || 654 irqflags & desc->action->flags & IRQF_SHARED) 655 canrequest = 1; 656 } 657 irq_put_desc_unlock(desc, flags); 658 return canrequest; 659 } 660 661 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags) 662 { 663 struct irq_chip *chip = desc->irq_data.chip; 664 int ret, unmask = 0; 665 666 if (!chip || !chip->irq_set_type) { 667 /* 668 * IRQF_TRIGGER_* but the PIC does not support multiple 669 * flow-types? 670 */ 671 pr_debug("No set_type function for IRQ %d (%s)\n", 672 irq_desc_get_irq(desc), 673 chip ? (chip->name ? : "unknown") : "unknown"); 674 return 0; 675 } 676 677 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) { 678 if (!irqd_irq_masked(&desc->irq_data)) 679 mask_irq(desc); 680 if (!irqd_irq_disabled(&desc->irq_data)) 681 unmask = 1; 682 } 683 684 /* Mask all flags except trigger mode */ 685 flags &= IRQ_TYPE_SENSE_MASK; 686 ret = chip->irq_set_type(&desc->irq_data, flags); 687 688 switch (ret) { 689 case IRQ_SET_MASK_OK: 690 case IRQ_SET_MASK_OK_DONE: 691 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK); 692 irqd_set(&desc->irq_data, flags); 693 694 case IRQ_SET_MASK_OK_NOCOPY: 695 flags = irqd_get_trigger_type(&desc->irq_data); 696 irq_settings_set_trigger_mask(desc, flags); 697 irqd_clear(&desc->irq_data, IRQD_LEVEL); 698 irq_settings_clr_level(desc); 699 if (flags & IRQ_TYPE_LEVEL_MASK) { 700 irq_settings_set_level(desc); 701 irqd_set(&desc->irq_data, IRQD_LEVEL); 702 } 703 704 ret = 0; 705 break; 706 default: 707 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n", 708 flags, irq_desc_get_irq(desc), chip->irq_set_type); 709 } 710 if (unmask) 711 unmask_irq(desc); 712 return ret; 713 } 714 715 #ifdef CONFIG_HARDIRQS_SW_RESEND 716 int irq_set_parent(int irq, int parent_irq) 717 { 718 unsigned long flags; 719 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); 720 721 if (!desc) 722 return -EINVAL; 723 724 desc->parent_irq = parent_irq; 725 726 irq_put_desc_unlock(desc, flags); 727 return 0; 728 } 729 EXPORT_SYMBOL_GPL(irq_set_parent); 730 #endif 731 732 /* 733 * Default primary interrupt handler for threaded interrupts. Is 734 * assigned as primary handler when request_threaded_irq is called 735 * with handler == NULL. Useful for oneshot interrupts. 736 */ 737 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id) 738 { 739 return IRQ_WAKE_THREAD; 740 } 741 742 /* 743 * Primary handler for nested threaded interrupts. Should never be 744 * called. 745 */ 746 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id) 747 { 748 WARN(1, "Primary handler called for nested irq %d\n", irq); 749 return IRQ_NONE; 750 } 751 752 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id) 753 { 754 WARN(1, "Secondary action handler called for irq %d\n", irq); 755 return IRQ_NONE; 756 } 757 758 static int irq_wait_for_interrupt(struct irqaction *action) 759 { 760 set_current_state(TASK_INTERRUPTIBLE); 761 762 while (!kthread_should_stop()) { 763 764 if (test_and_clear_bit(IRQTF_RUNTHREAD, 765 &action->thread_flags)) { 766 __set_current_state(TASK_RUNNING); 767 return 0; 768 } 769 schedule(); 770 set_current_state(TASK_INTERRUPTIBLE); 771 } 772 __set_current_state(TASK_RUNNING); 773 return -1; 774 } 775 776 /* 777 * Oneshot interrupts keep the irq line masked until the threaded 778 * handler finished. unmask if the interrupt has not been disabled and 779 * is marked MASKED. 780 */ 781 static void irq_finalize_oneshot(struct irq_desc *desc, 782 struct irqaction *action) 783 { 784 if (!(desc->istate & IRQS_ONESHOT) || 785 action->handler == irq_forced_secondary_handler) 786 return; 787 again: 788 chip_bus_lock(desc); 789 raw_spin_lock_irq(&desc->lock); 790 791 /* 792 * Implausible though it may be we need to protect us against 793 * the following scenario: 794 * 795 * The thread is faster done than the hard interrupt handler 796 * on the other CPU. If we unmask the irq line then the 797 * interrupt can come in again and masks the line, leaves due 798 * to IRQS_INPROGRESS and the irq line is masked forever. 799 * 800 * This also serializes the state of shared oneshot handlers 801 * versus "desc->threads_onehsot |= action->thread_mask;" in 802 * irq_wake_thread(). See the comment there which explains the 803 * serialization. 804 */ 805 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) { 806 raw_spin_unlock_irq(&desc->lock); 807 chip_bus_sync_unlock(desc); 808 cpu_relax(); 809 goto again; 810 } 811 812 /* 813 * Now check again, whether the thread should run. Otherwise 814 * we would clear the threads_oneshot bit of this thread which 815 * was just set. 816 */ 817 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags)) 818 goto out_unlock; 819 820 desc->threads_oneshot &= ~action->thread_mask; 821 822 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) && 823 irqd_irq_masked(&desc->irq_data)) 824 unmask_threaded_irq(desc); 825 826 out_unlock: 827 raw_spin_unlock_irq(&desc->lock); 828 chip_bus_sync_unlock(desc); 829 } 830 831 #ifdef CONFIG_SMP 832 /* 833 * Check whether we need to change the affinity of the interrupt thread. 834 */ 835 static void 836 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) 837 { 838 cpumask_var_t mask; 839 bool valid = true; 840 841 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags)) 842 return; 843 844 /* 845 * In case we are out of memory we set IRQTF_AFFINITY again and 846 * try again next time 847 */ 848 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) { 849 set_bit(IRQTF_AFFINITY, &action->thread_flags); 850 return; 851 } 852 853 raw_spin_lock_irq(&desc->lock); 854 /* 855 * This code is triggered unconditionally. Check the affinity 856 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out. 857 */ 858 if (cpumask_available(desc->irq_common_data.affinity)) 859 cpumask_copy(mask, desc->irq_common_data.affinity); 860 else 861 valid = false; 862 raw_spin_unlock_irq(&desc->lock); 863 864 if (valid) 865 set_cpus_allowed_ptr(current, mask); 866 free_cpumask_var(mask); 867 } 868 #else 869 static inline void 870 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { } 871 #endif 872 873 /* 874 * Interrupts which are not explicitely requested as threaded 875 * interrupts rely on the implicit bh/preempt disable of the hard irq 876 * context. So we need to disable bh here to avoid deadlocks and other 877 * side effects. 878 */ 879 static irqreturn_t 880 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action) 881 { 882 irqreturn_t ret; 883 884 local_bh_disable(); 885 ret = action->thread_fn(action->irq, action->dev_id); 886 irq_finalize_oneshot(desc, action); 887 local_bh_enable(); 888 return ret; 889 } 890 891 /* 892 * Interrupts explicitly requested as threaded interrupts want to be 893 * preemtible - many of them need to sleep and wait for slow busses to 894 * complete. 895 */ 896 static irqreturn_t irq_thread_fn(struct irq_desc *desc, 897 struct irqaction *action) 898 { 899 irqreturn_t ret; 900 901 ret = action->thread_fn(action->irq, action->dev_id); 902 irq_finalize_oneshot(desc, action); 903 return ret; 904 } 905 906 static void wake_threads_waitq(struct irq_desc *desc) 907 { 908 if (atomic_dec_and_test(&desc->threads_active)) 909 wake_up(&desc->wait_for_threads); 910 } 911 912 static void irq_thread_dtor(struct callback_head *unused) 913 { 914 struct task_struct *tsk = current; 915 struct irq_desc *desc; 916 struct irqaction *action; 917 918 if (WARN_ON_ONCE(!(current->flags & PF_EXITING))) 919 return; 920 921 action = kthread_data(tsk); 922 923 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n", 924 tsk->comm, tsk->pid, action->irq); 925 926 927 desc = irq_to_desc(action->irq); 928 /* 929 * If IRQTF_RUNTHREAD is set, we need to decrement 930 * desc->threads_active and wake possible waiters. 931 */ 932 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags)) 933 wake_threads_waitq(desc); 934 935 /* Prevent a stale desc->threads_oneshot */ 936 irq_finalize_oneshot(desc, action); 937 } 938 939 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action) 940 { 941 struct irqaction *secondary = action->secondary; 942 943 if (WARN_ON_ONCE(!secondary)) 944 return; 945 946 raw_spin_lock_irq(&desc->lock); 947 __irq_wake_thread(desc, secondary); 948 raw_spin_unlock_irq(&desc->lock); 949 } 950 951 /* 952 * Interrupt handler thread 953 */ 954 static int irq_thread(void *data) 955 { 956 struct callback_head on_exit_work; 957 struct irqaction *action = data; 958 struct irq_desc *desc = irq_to_desc(action->irq); 959 irqreturn_t (*handler_fn)(struct irq_desc *desc, 960 struct irqaction *action); 961 962 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD, 963 &action->thread_flags)) 964 handler_fn = irq_forced_thread_fn; 965 else 966 handler_fn = irq_thread_fn; 967 968 init_task_work(&on_exit_work, irq_thread_dtor); 969 task_work_add(current, &on_exit_work, false); 970 971 irq_thread_check_affinity(desc, action); 972 973 while (!irq_wait_for_interrupt(action)) { 974 irqreturn_t action_ret; 975 976 irq_thread_check_affinity(desc, action); 977 978 action_ret = handler_fn(desc, action); 979 if (action_ret == IRQ_HANDLED) 980 atomic_inc(&desc->threads_handled); 981 if (action_ret == IRQ_WAKE_THREAD) 982 irq_wake_secondary(desc, action); 983 984 wake_threads_waitq(desc); 985 } 986 987 /* 988 * This is the regular exit path. __free_irq() is stopping the 989 * thread via kthread_stop() after calling 990 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the 991 * oneshot mask bit can be set. We cannot verify that as we 992 * cannot touch the oneshot mask at this point anymore as 993 * __setup_irq() might have given out currents thread_mask 994 * again. 995 */ 996 task_work_cancel(current, irq_thread_dtor); 997 return 0; 998 } 999 1000 /** 1001 * irq_wake_thread - wake the irq thread for the action identified by dev_id 1002 * @irq: Interrupt line 1003 * @dev_id: Device identity for which the thread should be woken 1004 * 1005 */ 1006 void irq_wake_thread(unsigned int irq, void *dev_id) 1007 { 1008 struct irq_desc *desc = irq_to_desc(irq); 1009 struct irqaction *action; 1010 unsigned long flags; 1011 1012 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1013 return; 1014 1015 raw_spin_lock_irqsave(&desc->lock, flags); 1016 for_each_action_of_desc(desc, action) { 1017 if (action->dev_id == dev_id) { 1018 if (action->thread) 1019 __irq_wake_thread(desc, action); 1020 break; 1021 } 1022 } 1023 raw_spin_unlock_irqrestore(&desc->lock, flags); 1024 } 1025 EXPORT_SYMBOL_GPL(irq_wake_thread); 1026 1027 static int irq_setup_forced_threading(struct irqaction *new) 1028 { 1029 if (!force_irqthreads) 1030 return 0; 1031 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)) 1032 return 0; 1033 1034 new->flags |= IRQF_ONESHOT; 1035 1036 /* 1037 * Handle the case where we have a real primary handler and a 1038 * thread handler. We force thread them as well by creating a 1039 * secondary action. 1040 */ 1041 if (new->handler != irq_default_primary_handler && new->thread_fn) { 1042 /* Allocate the secondary action */ 1043 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL); 1044 if (!new->secondary) 1045 return -ENOMEM; 1046 new->secondary->handler = irq_forced_secondary_handler; 1047 new->secondary->thread_fn = new->thread_fn; 1048 new->secondary->dev_id = new->dev_id; 1049 new->secondary->irq = new->irq; 1050 new->secondary->name = new->name; 1051 } 1052 /* Deal with the primary handler */ 1053 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags); 1054 new->thread_fn = new->handler; 1055 new->handler = irq_default_primary_handler; 1056 return 0; 1057 } 1058 1059 static int irq_request_resources(struct irq_desc *desc) 1060 { 1061 struct irq_data *d = &desc->irq_data; 1062 struct irq_chip *c = d->chip; 1063 1064 return c->irq_request_resources ? c->irq_request_resources(d) : 0; 1065 } 1066 1067 static void irq_release_resources(struct irq_desc *desc) 1068 { 1069 struct irq_data *d = &desc->irq_data; 1070 struct irq_chip *c = d->chip; 1071 1072 if (c->irq_release_resources) 1073 c->irq_release_resources(d); 1074 } 1075 1076 static int 1077 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary) 1078 { 1079 struct task_struct *t; 1080 struct sched_param param = { 1081 .sched_priority = MAX_USER_RT_PRIO/2, 1082 }; 1083 1084 if (!secondary) { 1085 t = kthread_create(irq_thread, new, "irq/%d-%s", irq, 1086 new->name); 1087 } else { 1088 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq, 1089 new->name); 1090 param.sched_priority -= 1; 1091 } 1092 1093 if (IS_ERR(t)) 1094 return PTR_ERR(t); 1095 1096 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m); 1097 1098 /* 1099 * We keep the reference to the task struct even if 1100 * the thread dies to avoid that the interrupt code 1101 * references an already freed task_struct. 1102 */ 1103 get_task_struct(t); 1104 new->thread = t; 1105 /* 1106 * Tell the thread to set its affinity. This is 1107 * important for shared interrupt handlers as we do 1108 * not invoke setup_affinity() for the secondary 1109 * handlers as everything is already set up. Even for 1110 * interrupts marked with IRQF_NO_BALANCE this is 1111 * correct as we want the thread to move to the cpu(s) 1112 * on which the requesting code placed the interrupt. 1113 */ 1114 set_bit(IRQTF_AFFINITY, &new->thread_flags); 1115 return 0; 1116 } 1117 1118 /* 1119 * Internal function to register an irqaction - typically used to 1120 * allocate special interrupts that are part of the architecture. 1121 * 1122 * Locking rules: 1123 * 1124 * desc->request_mutex Provides serialization against a concurrent free_irq() 1125 * chip_bus_lock Provides serialization for slow bus operations 1126 * desc->lock Provides serialization against hard interrupts 1127 * 1128 * chip_bus_lock and desc->lock are sufficient for all other management and 1129 * interrupt related functions. desc->request_mutex solely serializes 1130 * request/free_irq(). 1131 */ 1132 static int 1133 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) 1134 { 1135 struct irqaction *old, **old_ptr; 1136 unsigned long flags, thread_mask = 0; 1137 int ret, nested, shared = 0; 1138 1139 if (!desc) 1140 return -EINVAL; 1141 1142 if (desc->irq_data.chip == &no_irq_chip) 1143 return -ENOSYS; 1144 if (!try_module_get(desc->owner)) 1145 return -ENODEV; 1146 1147 new->irq = irq; 1148 1149 /* 1150 * If the trigger type is not specified by the caller, 1151 * then use the default for this interrupt. 1152 */ 1153 if (!(new->flags & IRQF_TRIGGER_MASK)) 1154 new->flags |= irqd_get_trigger_type(&desc->irq_data); 1155 1156 /* 1157 * Check whether the interrupt nests into another interrupt 1158 * thread. 1159 */ 1160 nested = irq_settings_is_nested_thread(desc); 1161 if (nested) { 1162 if (!new->thread_fn) { 1163 ret = -EINVAL; 1164 goto out_mput; 1165 } 1166 /* 1167 * Replace the primary handler which was provided from 1168 * the driver for non nested interrupt handling by the 1169 * dummy function which warns when called. 1170 */ 1171 new->handler = irq_nested_primary_handler; 1172 } else { 1173 if (irq_settings_can_thread(desc)) { 1174 ret = irq_setup_forced_threading(new); 1175 if (ret) 1176 goto out_mput; 1177 } 1178 } 1179 1180 /* 1181 * Create a handler thread when a thread function is supplied 1182 * and the interrupt does not nest into another interrupt 1183 * thread. 1184 */ 1185 if (new->thread_fn && !nested) { 1186 ret = setup_irq_thread(new, irq, false); 1187 if (ret) 1188 goto out_mput; 1189 if (new->secondary) { 1190 ret = setup_irq_thread(new->secondary, irq, true); 1191 if (ret) 1192 goto out_thread; 1193 } 1194 } 1195 1196 /* 1197 * Drivers are often written to work w/o knowledge about the 1198 * underlying irq chip implementation, so a request for a 1199 * threaded irq without a primary hard irq context handler 1200 * requires the ONESHOT flag to be set. Some irq chips like 1201 * MSI based interrupts are per se one shot safe. Check the 1202 * chip flags, so we can avoid the unmask dance at the end of 1203 * the threaded handler for those. 1204 */ 1205 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE) 1206 new->flags &= ~IRQF_ONESHOT; 1207 1208 /* 1209 * Protects against a concurrent __free_irq() call which might wait 1210 * for synchronize_irq() to complete without holding the optional 1211 * chip bus lock and desc->lock. 1212 */ 1213 mutex_lock(&desc->request_mutex); 1214 1215 /* 1216 * Acquire bus lock as the irq_request_resources() callback below 1217 * might rely on the serialization or the magic power management 1218 * functions which are abusing the irq_bus_lock() callback, 1219 */ 1220 chip_bus_lock(desc); 1221 1222 /* First installed action requests resources. */ 1223 if (!desc->action) { 1224 ret = irq_request_resources(desc); 1225 if (ret) { 1226 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n", 1227 new->name, irq, desc->irq_data.chip->name); 1228 goto out_bus_unlock; 1229 } 1230 } 1231 1232 /* 1233 * The following block of code has to be executed atomically 1234 * protected against a concurrent interrupt and any of the other 1235 * management calls which are not serialized via 1236 * desc->request_mutex or the optional bus lock. 1237 */ 1238 raw_spin_lock_irqsave(&desc->lock, flags); 1239 old_ptr = &desc->action; 1240 old = *old_ptr; 1241 if (old) { 1242 /* 1243 * Can't share interrupts unless both agree to and are 1244 * the same type (level, edge, polarity). So both flag 1245 * fields must have IRQF_SHARED set and the bits which 1246 * set the trigger type must match. Also all must 1247 * agree on ONESHOT. 1248 */ 1249 unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data); 1250 1251 if (!((old->flags & new->flags) & IRQF_SHARED) || 1252 (oldtype != (new->flags & IRQF_TRIGGER_MASK)) || 1253 ((old->flags ^ new->flags) & IRQF_ONESHOT)) 1254 goto mismatch; 1255 1256 /* All handlers must agree on per-cpuness */ 1257 if ((old->flags & IRQF_PERCPU) != 1258 (new->flags & IRQF_PERCPU)) 1259 goto mismatch; 1260 1261 /* add new interrupt at end of irq queue */ 1262 do { 1263 /* 1264 * Or all existing action->thread_mask bits, 1265 * so we can find the next zero bit for this 1266 * new action. 1267 */ 1268 thread_mask |= old->thread_mask; 1269 old_ptr = &old->next; 1270 old = *old_ptr; 1271 } while (old); 1272 shared = 1; 1273 } 1274 1275 /* 1276 * Setup the thread mask for this irqaction for ONESHOT. For 1277 * !ONESHOT irqs the thread mask is 0 so we can avoid a 1278 * conditional in irq_wake_thread(). 1279 */ 1280 if (new->flags & IRQF_ONESHOT) { 1281 /* 1282 * Unlikely to have 32 resp 64 irqs sharing one line, 1283 * but who knows. 1284 */ 1285 if (thread_mask == ~0UL) { 1286 ret = -EBUSY; 1287 goto out_unlock; 1288 } 1289 /* 1290 * The thread_mask for the action is or'ed to 1291 * desc->thread_active to indicate that the 1292 * IRQF_ONESHOT thread handler has been woken, but not 1293 * yet finished. The bit is cleared when a thread 1294 * completes. When all threads of a shared interrupt 1295 * line have completed desc->threads_active becomes 1296 * zero and the interrupt line is unmasked. See 1297 * handle.c:irq_wake_thread() for further information. 1298 * 1299 * If no thread is woken by primary (hard irq context) 1300 * interrupt handlers, then desc->threads_active is 1301 * also checked for zero to unmask the irq line in the 1302 * affected hard irq flow handlers 1303 * (handle_[fasteoi|level]_irq). 1304 * 1305 * The new action gets the first zero bit of 1306 * thread_mask assigned. See the loop above which or's 1307 * all existing action->thread_mask bits. 1308 */ 1309 new->thread_mask = 1UL << ffz(thread_mask); 1310 1311 } else if (new->handler == irq_default_primary_handler && 1312 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) { 1313 /* 1314 * The interrupt was requested with handler = NULL, so 1315 * we use the default primary handler for it. But it 1316 * does not have the oneshot flag set. In combination 1317 * with level interrupts this is deadly, because the 1318 * default primary handler just wakes the thread, then 1319 * the irq lines is reenabled, but the device still 1320 * has the level irq asserted. Rinse and repeat.... 1321 * 1322 * While this works for edge type interrupts, we play 1323 * it safe and reject unconditionally because we can't 1324 * say for sure which type this interrupt really 1325 * has. The type flags are unreliable as the 1326 * underlying chip implementation can override them. 1327 */ 1328 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n", 1329 irq); 1330 ret = -EINVAL; 1331 goto out_unlock; 1332 } 1333 1334 if (!shared) { 1335 init_waitqueue_head(&desc->wait_for_threads); 1336 1337 /* Setup the type (level, edge polarity) if configured: */ 1338 if (new->flags & IRQF_TRIGGER_MASK) { 1339 ret = __irq_set_trigger(desc, 1340 new->flags & IRQF_TRIGGER_MASK); 1341 1342 if (ret) 1343 goto out_unlock; 1344 } 1345 1346 /* 1347 * Activate the interrupt. That activation must happen 1348 * independently of IRQ_NOAUTOEN. request_irq() can fail 1349 * and the callers are supposed to handle 1350 * that. enable_irq() of an interrupt requested with 1351 * IRQ_NOAUTOEN is not supposed to fail. The activation 1352 * keeps it in shutdown mode, it merily associates 1353 * resources if necessary and if that's not possible it 1354 * fails. Interrupts which are in managed shutdown mode 1355 * will simply ignore that activation request. 1356 */ 1357 ret = irq_activate(desc); 1358 if (ret) 1359 goto out_unlock; 1360 1361 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \ 1362 IRQS_ONESHOT | IRQS_WAITING); 1363 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS); 1364 1365 if (new->flags & IRQF_PERCPU) { 1366 irqd_set(&desc->irq_data, IRQD_PER_CPU); 1367 irq_settings_set_per_cpu(desc); 1368 } 1369 1370 if (new->flags & IRQF_ONESHOT) 1371 desc->istate |= IRQS_ONESHOT; 1372 1373 /* Exclude IRQ from balancing if requested */ 1374 if (new->flags & IRQF_NOBALANCING) { 1375 irq_settings_set_no_balancing(desc); 1376 irqd_set(&desc->irq_data, IRQD_NO_BALANCING); 1377 } 1378 1379 if (irq_settings_can_autoenable(desc)) { 1380 irq_startup(desc, IRQ_RESEND, IRQ_START_COND); 1381 } else { 1382 /* 1383 * Shared interrupts do not go well with disabling 1384 * auto enable. The sharing interrupt might request 1385 * it while it's still disabled and then wait for 1386 * interrupts forever. 1387 */ 1388 WARN_ON_ONCE(new->flags & IRQF_SHARED); 1389 /* Undo nested disables: */ 1390 desc->depth = 1; 1391 } 1392 1393 } else if (new->flags & IRQF_TRIGGER_MASK) { 1394 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK; 1395 unsigned int omsk = irqd_get_trigger_type(&desc->irq_data); 1396 1397 if (nmsk != omsk) 1398 /* hope the handler works with current trigger mode */ 1399 pr_warn("irq %d uses trigger mode %u; requested %u\n", 1400 irq, omsk, nmsk); 1401 } 1402 1403 *old_ptr = new; 1404 1405 irq_pm_install_action(desc, new); 1406 1407 /* Reset broken irq detection when installing new handler */ 1408 desc->irq_count = 0; 1409 desc->irqs_unhandled = 0; 1410 1411 /* 1412 * Check whether we disabled the irq via the spurious handler 1413 * before. Reenable it and give it another chance. 1414 */ 1415 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) { 1416 desc->istate &= ~IRQS_SPURIOUS_DISABLED; 1417 __enable_irq(desc); 1418 } 1419 1420 raw_spin_unlock_irqrestore(&desc->lock, flags); 1421 chip_bus_sync_unlock(desc); 1422 mutex_unlock(&desc->request_mutex); 1423 1424 irq_setup_timings(desc, new); 1425 1426 /* 1427 * Strictly no need to wake it up, but hung_task complains 1428 * when no hard interrupt wakes the thread up. 1429 */ 1430 if (new->thread) 1431 wake_up_process(new->thread); 1432 if (new->secondary) 1433 wake_up_process(new->secondary->thread); 1434 1435 register_irq_proc(irq, desc); 1436 new->dir = NULL; 1437 register_handler_proc(irq, new); 1438 return 0; 1439 1440 mismatch: 1441 if (!(new->flags & IRQF_PROBE_SHARED)) { 1442 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n", 1443 irq, new->flags, new->name, old->flags, old->name); 1444 #ifdef CONFIG_DEBUG_SHIRQ 1445 dump_stack(); 1446 #endif 1447 } 1448 ret = -EBUSY; 1449 1450 out_unlock: 1451 raw_spin_unlock_irqrestore(&desc->lock, flags); 1452 1453 if (!desc->action) 1454 irq_release_resources(desc); 1455 out_bus_unlock: 1456 chip_bus_sync_unlock(desc); 1457 mutex_unlock(&desc->request_mutex); 1458 1459 out_thread: 1460 if (new->thread) { 1461 struct task_struct *t = new->thread; 1462 1463 new->thread = NULL; 1464 kthread_stop(t); 1465 put_task_struct(t); 1466 } 1467 if (new->secondary && new->secondary->thread) { 1468 struct task_struct *t = new->secondary->thread; 1469 1470 new->secondary->thread = NULL; 1471 kthread_stop(t); 1472 put_task_struct(t); 1473 } 1474 out_mput: 1475 module_put(desc->owner); 1476 return ret; 1477 } 1478 1479 /** 1480 * setup_irq - setup an interrupt 1481 * @irq: Interrupt line to setup 1482 * @act: irqaction for the interrupt 1483 * 1484 * Used to statically setup interrupts in the early boot process. 1485 */ 1486 int setup_irq(unsigned int irq, struct irqaction *act) 1487 { 1488 int retval; 1489 struct irq_desc *desc = irq_to_desc(irq); 1490 1491 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1492 return -EINVAL; 1493 1494 retval = irq_chip_pm_get(&desc->irq_data); 1495 if (retval < 0) 1496 return retval; 1497 1498 retval = __setup_irq(irq, desc, act); 1499 1500 if (retval) 1501 irq_chip_pm_put(&desc->irq_data); 1502 1503 return retval; 1504 } 1505 EXPORT_SYMBOL_GPL(setup_irq); 1506 1507 /* 1508 * Internal function to unregister an irqaction - used to free 1509 * regular and special interrupts that are part of the architecture. 1510 */ 1511 static struct irqaction *__free_irq(unsigned int irq, void *dev_id) 1512 { 1513 struct irq_desc *desc = irq_to_desc(irq); 1514 struct irqaction *action, **action_ptr; 1515 unsigned long flags; 1516 1517 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); 1518 1519 if (!desc) 1520 return NULL; 1521 1522 mutex_lock(&desc->request_mutex); 1523 chip_bus_lock(desc); 1524 raw_spin_lock_irqsave(&desc->lock, flags); 1525 1526 /* 1527 * There can be multiple actions per IRQ descriptor, find the right 1528 * one based on the dev_id: 1529 */ 1530 action_ptr = &desc->action; 1531 for (;;) { 1532 action = *action_ptr; 1533 1534 if (!action) { 1535 WARN(1, "Trying to free already-free IRQ %d\n", irq); 1536 raw_spin_unlock_irqrestore(&desc->lock, flags); 1537 chip_bus_sync_unlock(desc); 1538 mutex_unlock(&desc->request_mutex); 1539 return NULL; 1540 } 1541 1542 if (action->dev_id == dev_id) 1543 break; 1544 action_ptr = &action->next; 1545 } 1546 1547 /* Found it - now remove it from the list of entries: */ 1548 *action_ptr = action->next; 1549 1550 irq_pm_remove_action(desc, action); 1551 1552 /* If this was the last handler, shut down the IRQ line: */ 1553 if (!desc->action) { 1554 irq_settings_clr_disable_unlazy(desc); 1555 irq_shutdown(desc); 1556 } 1557 1558 #ifdef CONFIG_SMP 1559 /* make sure affinity_hint is cleaned up */ 1560 if (WARN_ON_ONCE(desc->affinity_hint)) 1561 desc->affinity_hint = NULL; 1562 #endif 1563 1564 raw_spin_unlock_irqrestore(&desc->lock, flags); 1565 /* 1566 * Drop bus_lock here so the changes which were done in the chip 1567 * callbacks above are synced out to the irq chips which hang 1568 * behind a slow bus (I2C, SPI) before calling synchronize_irq(). 1569 * 1570 * Aside of that the bus_lock can also be taken from the threaded 1571 * handler in irq_finalize_oneshot() which results in a deadlock 1572 * because synchronize_irq() would wait forever for the thread to 1573 * complete, which is blocked on the bus lock. 1574 * 1575 * The still held desc->request_mutex() protects against a 1576 * concurrent request_irq() of this irq so the release of resources 1577 * and timing data is properly serialized. 1578 */ 1579 chip_bus_sync_unlock(desc); 1580 1581 unregister_handler_proc(irq, action); 1582 1583 /* Make sure it's not being used on another CPU: */ 1584 synchronize_irq(irq); 1585 1586 #ifdef CONFIG_DEBUG_SHIRQ 1587 /* 1588 * It's a shared IRQ -- the driver ought to be prepared for an IRQ 1589 * event to happen even now it's being freed, so let's make sure that 1590 * is so by doing an extra call to the handler .... 1591 * 1592 * ( We do this after actually deregistering it, to make sure that a 1593 * 'real' IRQ doesn't run in * parallel with our fake. ) 1594 */ 1595 if (action->flags & IRQF_SHARED) { 1596 local_irq_save(flags); 1597 action->handler(irq, dev_id); 1598 local_irq_restore(flags); 1599 } 1600 #endif 1601 1602 if (action->thread) { 1603 kthread_stop(action->thread); 1604 put_task_struct(action->thread); 1605 if (action->secondary && action->secondary->thread) { 1606 kthread_stop(action->secondary->thread); 1607 put_task_struct(action->secondary->thread); 1608 } 1609 } 1610 1611 /* Last action releases resources */ 1612 if (!desc->action) { 1613 /* 1614 * Reaquire bus lock as irq_release_resources() might 1615 * require it to deallocate resources over the slow bus. 1616 */ 1617 chip_bus_lock(desc); 1618 irq_release_resources(desc); 1619 chip_bus_sync_unlock(desc); 1620 irq_remove_timings(desc); 1621 } 1622 1623 mutex_unlock(&desc->request_mutex); 1624 1625 irq_chip_pm_put(&desc->irq_data); 1626 module_put(desc->owner); 1627 kfree(action->secondary); 1628 return action; 1629 } 1630 1631 /** 1632 * remove_irq - free an interrupt 1633 * @irq: Interrupt line to free 1634 * @act: irqaction for the interrupt 1635 * 1636 * Used to remove interrupts statically setup by the early boot process. 1637 */ 1638 void remove_irq(unsigned int irq, struct irqaction *act) 1639 { 1640 struct irq_desc *desc = irq_to_desc(irq); 1641 1642 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1643 __free_irq(irq, act->dev_id); 1644 } 1645 EXPORT_SYMBOL_GPL(remove_irq); 1646 1647 /** 1648 * free_irq - free an interrupt allocated with request_irq 1649 * @irq: Interrupt line to free 1650 * @dev_id: Device identity to free 1651 * 1652 * Remove an interrupt handler. The handler is removed and if the 1653 * interrupt line is no longer in use by any driver it is disabled. 1654 * On a shared IRQ the caller must ensure the interrupt is disabled 1655 * on the card it drives before calling this function. The function 1656 * does not return until any executing interrupts for this IRQ 1657 * have completed. 1658 * 1659 * This function must not be called from interrupt context. 1660 * 1661 * Returns the devname argument passed to request_irq. 1662 */ 1663 const void *free_irq(unsigned int irq, void *dev_id) 1664 { 1665 struct irq_desc *desc = irq_to_desc(irq); 1666 struct irqaction *action; 1667 const char *devname; 1668 1669 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1670 return NULL; 1671 1672 #ifdef CONFIG_SMP 1673 if (WARN_ON(desc->affinity_notify)) 1674 desc->affinity_notify = NULL; 1675 #endif 1676 1677 action = __free_irq(irq, dev_id); 1678 1679 if (!action) 1680 return NULL; 1681 1682 devname = action->name; 1683 kfree(action); 1684 return devname; 1685 } 1686 EXPORT_SYMBOL(free_irq); 1687 1688 /** 1689 * request_threaded_irq - allocate an interrupt line 1690 * @irq: Interrupt line to allocate 1691 * @handler: Function to be called when the IRQ occurs. 1692 * Primary handler for threaded interrupts 1693 * If NULL and thread_fn != NULL the default 1694 * primary handler is installed 1695 * @thread_fn: Function called from the irq handler thread 1696 * If NULL, no irq thread is created 1697 * @irqflags: Interrupt type flags 1698 * @devname: An ascii name for the claiming device 1699 * @dev_id: A cookie passed back to the handler function 1700 * 1701 * This call allocates interrupt resources and enables the 1702 * interrupt line and IRQ handling. From the point this 1703 * call is made your handler function may be invoked. Since 1704 * your handler function must clear any interrupt the board 1705 * raises, you must take care both to initialise your hardware 1706 * and to set up the interrupt handler in the right order. 1707 * 1708 * If you want to set up a threaded irq handler for your device 1709 * then you need to supply @handler and @thread_fn. @handler is 1710 * still called in hard interrupt context and has to check 1711 * whether the interrupt originates from the device. If yes it 1712 * needs to disable the interrupt on the device and return 1713 * IRQ_WAKE_THREAD which will wake up the handler thread and run 1714 * @thread_fn. This split handler design is necessary to support 1715 * shared interrupts. 1716 * 1717 * Dev_id must be globally unique. Normally the address of the 1718 * device data structure is used as the cookie. Since the handler 1719 * receives this value it makes sense to use it. 1720 * 1721 * If your interrupt is shared you must pass a non NULL dev_id 1722 * as this is required when freeing the interrupt. 1723 * 1724 * Flags: 1725 * 1726 * IRQF_SHARED Interrupt is shared 1727 * IRQF_TRIGGER_* Specify active edge(s) or level 1728 * 1729 */ 1730 int request_threaded_irq(unsigned int irq, irq_handler_t handler, 1731 irq_handler_t thread_fn, unsigned long irqflags, 1732 const char *devname, void *dev_id) 1733 { 1734 struct irqaction *action; 1735 struct irq_desc *desc; 1736 int retval; 1737 1738 if (irq == IRQ_NOTCONNECTED) 1739 return -ENOTCONN; 1740 1741 /* 1742 * Sanity-check: shared interrupts must pass in a real dev-ID, 1743 * otherwise we'll have trouble later trying to figure out 1744 * which interrupt is which (messes up the interrupt freeing 1745 * logic etc). 1746 * 1747 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and 1748 * it cannot be set along with IRQF_NO_SUSPEND. 1749 */ 1750 if (((irqflags & IRQF_SHARED) && !dev_id) || 1751 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) || 1752 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND))) 1753 return -EINVAL; 1754 1755 desc = irq_to_desc(irq); 1756 if (!desc) 1757 return -EINVAL; 1758 1759 if (!irq_settings_can_request(desc) || 1760 WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1761 return -EINVAL; 1762 1763 if (!handler) { 1764 if (!thread_fn) 1765 return -EINVAL; 1766 handler = irq_default_primary_handler; 1767 } 1768 1769 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); 1770 if (!action) 1771 return -ENOMEM; 1772 1773 action->handler = handler; 1774 action->thread_fn = thread_fn; 1775 action->flags = irqflags; 1776 action->name = devname; 1777 action->dev_id = dev_id; 1778 1779 retval = irq_chip_pm_get(&desc->irq_data); 1780 if (retval < 0) { 1781 kfree(action); 1782 return retval; 1783 } 1784 1785 retval = __setup_irq(irq, desc, action); 1786 1787 if (retval) { 1788 irq_chip_pm_put(&desc->irq_data); 1789 kfree(action->secondary); 1790 kfree(action); 1791 } 1792 1793 #ifdef CONFIG_DEBUG_SHIRQ_FIXME 1794 if (!retval && (irqflags & IRQF_SHARED)) { 1795 /* 1796 * It's a shared IRQ -- the driver ought to be prepared for it 1797 * to happen immediately, so let's make sure.... 1798 * We disable the irq to make sure that a 'real' IRQ doesn't 1799 * run in parallel with our fake. 1800 */ 1801 unsigned long flags; 1802 1803 disable_irq(irq); 1804 local_irq_save(flags); 1805 1806 handler(irq, dev_id); 1807 1808 local_irq_restore(flags); 1809 enable_irq(irq); 1810 } 1811 #endif 1812 return retval; 1813 } 1814 EXPORT_SYMBOL(request_threaded_irq); 1815 1816 /** 1817 * request_any_context_irq - allocate an interrupt line 1818 * @irq: Interrupt line to allocate 1819 * @handler: Function to be called when the IRQ occurs. 1820 * Threaded handler for threaded interrupts. 1821 * @flags: Interrupt type flags 1822 * @name: An ascii name for the claiming device 1823 * @dev_id: A cookie passed back to the handler function 1824 * 1825 * This call allocates interrupt resources and enables the 1826 * interrupt line and IRQ handling. It selects either a 1827 * hardirq or threaded handling method depending on the 1828 * context. 1829 * 1830 * On failure, it returns a negative value. On success, 1831 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED. 1832 */ 1833 int request_any_context_irq(unsigned int irq, irq_handler_t handler, 1834 unsigned long flags, const char *name, void *dev_id) 1835 { 1836 struct irq_desc *desc; 1837 int ret; 1838 1839 if (irq == IRQ_NOTCONNECTED) 1840 return -ENOTCONN; 1841 1842 desc = irq_to_desc(irq); 1843 if (!desc) 1844 return -EINVAL; 1845 1846 if (irq_settings_is_nested_thread(desc)) { 1847 ret = request_threaded_irq(irq, NULL, handler, 1848 flags, name, dev_id); 1849 return !ret ? IRQC_IS_NESTED : ret; 1850 } 1851 1852 ret = request_irq(irq, handler, flags, name, dev_id); 1853 return !ret ? IRQC_IS_HARDIRQ : ret; 1854 } 1855 EXPORT_SYMBOL_GPL(request_any_context_irq); 1856 1857 void enable_percpu_irq(unsigned int irq, unsigned int type) 1858 { 1859 unsigned int cpu = smp_processor_id(); 1860 unsigned long flags; 1861 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); 1862 1863 if (!desc) 1864 return; 1865 1866 /* 1867 * If the trigger type is not specified by the caller, then 1868 * use the default for this interrupt. 1869 */ 1870 type &= IRQ_TYPE_SENSE_MASK; 1871 if (type == IRQ_TYPE_NONE) 1872 type = irqd_get_trigger_type(&desc->irq_data); 1873 1874 if (type != IRQ_TYPE_NONE) { 1875 int ret; 1876 1877 ret = __irq_set_trigger(desc, type); 1878 1879 if (ret) { 1880 WARN(1, "failed to set type for IRQ%d\n", irq); 1881 goto out; 1882 } 1883 } 1884 1885 irq_percpu_enable(desc, cpu); 1886 out: 1887 irq_put_desc_unlock(desc, flags); 1888 } 1889 EXPORT_SYMBOL_GPL(enable_percpu_irq); 1890 1891 /** 1892 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled 1893 * @irq: Linux irq number to check for 1894 * 1895 * Must be called from a non migratable context. Returns the enable 1896 * state of a per cpu interrupt on the current cpu. 1897 */ 1898 bool irq_percpu_is_enabled(unsigned int irq) 1899 { 1900 unsigned int cpu = smp_processor_id(); 1901 struct irq_desc *desc; 1902 unsigned long flags; 1903 bool is_enabled; 1904 1905 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); 1906 if (!desc) 1907 return false; 1908 1909 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled); 1910 irq_put_desc_unlock(desc, flags); 1911 1912 return is_enabled; 1913 } 1914 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled); 1915 1916 void disable_percpu_irq(unsigned int irq) 1917 { 1918 unsigned int cpu = smp_processor_id(); 1919 unsigned long flags; 1920 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); 1921 1922 if (!desc) 1923 return; 1924 1925 irq_percpu_disable(desc, cpu); 1926 irq_put_desc_unlock(desc, flags); 1927 } 1928 EXPORT_SYMBOL_GPL(disable_percpu_irq); 1929 1930 /* 1931 * Internal function to unregister a percpu irqaction. 1932 */ 1933 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id) 1934 { 1935 struct irq_desc *desc = irq_to_desc(irq); 1936 struct irqaction *action; 1937 unsigned long flags; 1938 1939 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); 1940 1941 if (!desc) 1942 return NULL; 1943 1944 raw_spin_lock_irqsave(&desc->lock, flags); 1945 1946 action = desc->action; 1947 if (!action || action->percpu_dev_id != dev_id) { 1948 WARN(1, "Trying to free already-free IRQ %d\n", irq); 1949 goto bad; 1950 } 1951 1952 if (!cpumask_empty(desc->percpu_enabled)) { 1953 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n", 1954 irq, cpumask_first(desc->percpu_enabled)); 1955 goto bad; 1956 } 1957 1958 /* Found it - now remove it from the list of entries: */ 1959 desc->action = NULL; 1960 1961 raw_spin_unlock_irqrestore(&desc->lock, flags); 1962 1963 unregister_handler_proc(irq, action); 1964 1965 irq_chip_pm_put(&desc->irq_data); 1966 module_put(desc->owner); 1967 return action; 1968 1969 bad: 1970 raw_spin_unlock_irqrestore(&desc->lock, flags); 1971 return NULL; 1972 } 1973 1974 /** 1975 * remove_percpu_irq - free a per-cpu interrupt 1976 * @irq: Interrupt line to free 1977 * @act: irqaction for the interrupt 1978 * 1979 * Used to remove interrupts statically setup by the early boot process. 1980 */ 1981 void remove_percpu_irq(unsigned int irq, struct irqaction *act) 1982 { 1983 struct irq_desc *desc = irq_to_desc(irq); 1984 1985 if (desc && irq_settings_is_per_cpu_devid(desc)) 1986 __free_percpu_irq(irq, act->percpu_dev_id); 1987 } 1988 1989 /** 1990 * free_percpu_irq - free an interrupt allocated with request_percpu_irq 1991 * @irq: Interrupt line to free 1992 * @dev_id: Device identity to free 1993 * 1994 * Remove a percpu interrupt handler. The handler is removed, but 1995 * the interrupt line is not disabled. This must be done on each 1996 * CPU before calling this function. The function does not return 1997 * until any executing interrupts for this IRQ have completed. 1998 * 1999 * This function must not be called from interrupt context. 2000 */ 2001 void free_percpu_irq(unsigned int irq, void __percpu *dev_id) 2002 { 2003 struct irq_desc *desc = irq_to_desc(irq); 2004 2005 if (!desc || !irq_settings_is_per_cpu_devid(desc)) 2006 return; 2007 2008 chip_bus_lock(desc); 2009 kfree(__free_percpu_irq(irq, dev_id)); 2010 chip_bus_sync_unlock(desc); 2011 } 2012 EXPORT_SYMBOL_GPL(free_percpu_irq); 2013 2014 /** 2015 * setup_percpu_irq - setup a per-cpu interrupt 2016 * @irq: Interrupt line to setup 2017 * @act: irqaction for the interrupt 2018 * 2019 * Used to statically setup per-cpu interrupts in the early boot process. 2020 */ 2021 int setup_percpu_irq(unsigned int irq, struct irqaction *act) 2022 { 2023 struct irq_desc *desc = irq_to_desc(irq); 2024 int retval; 2025 2026 if (!desc || !irq_settings_is_per_cpu_devid(desc)) 2027 return -EINVAL; 2028 2029 retval = irq_chip_pm_get(&desc->irq_data); 2030 if (retval < 0) 2031 return retval; 2032 2033 retval = __setup_irq(irq, desc, act); 2034 2035 if (retval) 2036 irq_chip_pm_put(&desc->irq_data); 2037 2038 return retval; 2039 } 2040 2041 /** 2042 * __request_percpu_irq - allocate a percpu interrupt line 2043 * @irq: Interrupt line to allocate 2044 * @handler: Function to be called when the IRQ occurs. 2045 * @flags: Interrupt type flags (IRQF_TIMER only) 2046 * @devname: An ascii name for the claiming device 2047 * @dev_id: A percpu cookie passed back to the handler function 2048 * 2049 * This call allocates interrupt resources and enables the 2050 * interrupt on the local CPU. If the interrupt is supposed to be 2051 * enabled on other CPUs, it has to be done on each CPU using 2052 * enable_percpu_irq(). 2053 * 2054 * Dev_id must be globally unique. It is a per-cpu variable, and 2055 * the handler gets called with the interrupted CPU's instance of 2056 * that variable. 2057 */ 2058 int __request_percpu_irq(unsigned int irq, irq_handler_t handler, 2059 unsigned long flags, const char *devname, 2060 void __percpu *dev_id) 2061 { 2062 struct irqaction *action; 2063 struct irq_desc *desc; 2064 int retval; 2065 2066 if (!dev_id) 2067 return -EINVAL; 2068 2069 desc = irq_to_desc(irq); 2070 if (!desc || !irq_settings_can_request(desc) || 2071 !irq_settings_is_per_cpu_devid(desc)) 2072 return -EINVAL; 2073 2074 if (flags && flags != IRQF_TIMER) 2075 return -EINVAL; 2076 2077 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); 2078 if (!action) 2079 return -ENOMEM; 2080 2081 action->handler = handler; 2082 action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND; 2083 action->name = devname; 2084 action->percpu_dev_id = dev_id; 2085 2086 retval = irq_chip_pm_get(&desc->irq_data); 2087 if (retval < 0) { 2088 kfree(action); 2089 return retval; 2090 } 2091 2092 retval = __setup_irq(irq, desc, action); 2093 2094 if (retval) { 2095 irq_chip_pm_put(&desc->irq_data); 2096 kfree(action); 2097 } 2098 2099 return retval; 2100 } 2101 EXPORT_SYMBOL_GPL(__request_percpu_irq); 2102 2103 /** 2104 * irq_get_irqchip_state - returns the irqchip state of a interrupt. 2105 * @irq: Interrupt line that is forwarded to a VM 2106 * @which: One of IRQCHIP_STATE_* the caller wants to know about 2107 * @state: a pointer to a boolean where the state is to be storeed 2108 * 2109 * This call snapshots the internal irqchip state of an 2110 * interrupt, returning into @state the bit corresponding to 2111 * stage @which 2112 * 2113 * This function should be called with preemption disabled if the 2114 * interrupt controller has per-cpu registers. 2115 */ 2116 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, 2117 bool *state) 2118 { 2119 struct irq_desc *desc; 2120 struct irq_data *data; 2121 struct irq_chip *chip; 2122 unsigned long flags; 2123 int err = -EINVAL; 2124 2125 desc = irq_get_desc_buslock(irq, &flags, 0); 2126 if (!desc) 2127 return err; 2128 2129 data = irq_desc_get_irq_data(desc); 2130 2131 do { 2132 chip = irq_data_get_irq_chip(data); 2133 if (chip->irq_get_irqchip_state) 2134 break; 2135 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY 2136 data = data->parent_data; 2137 #else 2138 data = NULL; 2139 #endif 2140 } while (data); 2141 2142 if (data) 2143 err = chip->irq_get_irqchip_state(data, which, state); 2144 2145 irq_put_desc_busunlock(desc, flags); 2146 return err; 2147 } 2148 EXPORT_SYMBOL_GPL(irq_get_irqchip_state); 2149 2150 /** 2151 * irq_set_irqchip_state - set the state of a forwarded interrupt. 2152 * @irq: Interrupt line that is forwarded to a VM 2153 * @which: State to be restored (one of IRQCHIP_STATE_*) 2154 * @val: Value corresponding to @which 2155 * 2156 * This call sets the internal irqchip state of an interrupt, 2157 * depending on the value of @which. 2158 * 2159 * This function should be called with preemption disabled if the 2160 * interrupt controller has per-cpu registers. 2161 */ 2162 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, 2163 bool val) 2164 { 2165 struct irq_desc *desc; 2166 struct irq_data *data; 2167 struct irq_chip *chip; 2168 unsigned long flags; 2169 int err = -EINVAL; 2170 2171 desc = irq_get_desc_buslock(irq, &flags, 0); 2172 if (!desc) 2173 return err; 2174 2175 data = irq_desc_get_irq_data(desc); 2176 2177 do { 2178 chip = irq_data_get_irq_chip(data); 2179 if (chip->irq_set_irqchip_state) 2180 break; 2181 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY 2182 data = data->parent_data; 2183 #else 2184 data = NULL; 2185 #endif 2186 } while (data); 2187 2188 if (data) 2189 err = chip->irq_set_irqchip_state(data, which, val); 2190 2191 irq_put_desc_busunlock(desc, flags); 2192 return err; 2193 } 2194 EXPORT_SYMBOL_GPL(irq_set_irqchip_state); 2195